#include "EventLoopThreadPool.h"
#include "EventLoopThread.h"
#include <memory>

EventLoopThreadPool::EventLoopThreadPool(EventLoop* baseLoop, const std::string& nameArg)
    : baseLoop_(baseLoop)
    , name_(nameArg)
    , started_(false)
    , numThreads_(0)
    , next_(0)
{}

EventLoopThreadPool::~EventLoopThreadPool() {}

void EventLoopThreadPool::start(const ThreadInitCallback& cb)
{
    started_ = true;
    for (int i = 0; i < numThreads_; ++i)
    {
        char buf[name_.size() + 32];
        snprintf(buf, sizeof buf, "%s%d", name_.c_str(), i);
        EventLoopThread* t = new EventLoopThread(cb, buf);
        threads_.push_back(std::unique_ptr<EventLoopThread>(t));
        loops_.push_back(t->startLoop()); //底层创建线程， 绑定一个新的EventLoop，并返回该loop的地址
    }

    //整个服务端只有一个线程运行着baseloop
    if (numThreads_ == 0 && cb)
    {
        cb(baseLoop_);
    }
}

//如果工作在多线程中，baseLoop_默认以轮询的方式分配channel给subloop
EventLoop* EventLoopThreadPool::getNextLoop()
{
    EventLoop* loop = baseLoop_;

    if (!loops_.empty()) //通过轮询获取下一个处理事件的loop
    {
        loop = loops_[next_];
        ++next_;
        if (next_ >= loops_.size())
        {
            next_ = 0;
        }
    }
    return loop;
}

std::vector<EventLoop*> EventLoopThreadPool::getAllLoops()
{
    if (loops_.empty())
    {
        return std::vector<EventLoop*>(1, baseLoop_);
    }
    else
    {
        return loops_;
    }
}